A system of this kind is known from EP-B 71896 corresponding to U.S. Pat. No. 4,467,282. It can be used for receiving magnetic resonance signals and/or for generating rf magnetic fields. In the case of reception, the signal to noise ratio can be improved by as much as 3 dB in comparison with reception by one of these coils. When these coils are used in the transmission mode, circularly polarized magnetic rf fields can be generated thereby when rf currents which have been phase shifted 90.degree. with respect to one another are applied to the two rf coils, so that the required transmission power is halved. The rf fields should then extend not only perpendicularly to one another, but also perpendicular to the steady, uniform magnetic field which is indispensable for examinations based on magnetic resonance.
The rf coils of the known system are formed by saddle coils. These saddle coils are arranged on the surface of a cylindrical supporting means and generate magnetic fields which extend perpendicular to the axis of the supporting means. Taking into account that the longitudinal axis of a patient being examined should coincide with the axis of the supporting means it will be evident that such quadrature coils are only suitable for magnetic resonance examination apparatus in which the uniform, steady magnetic field generated by the magnetic resonance examination apparatus extends in the direction of the axis of the supporting means, i.e. in the longitudinal direction of the patient.